The LeCroy Model 612A is a new 12-channel, 200 MHz bandwidth, gain of
10 lin- ear amplifier packaged in a #1 NIM module. Representing a major advance
in fast amplifier stability, dynamic range, and general utility, the 612A
allows the experi- menter for the first time to consider the use of economical,
lower gain pho- tomultiplier tubes even in demanding direct-coupled ADC applications.
The Model 612A offers a built-in fan-out of two, simplifying simultaneous
use of the same photomultiplier signal for both analog and logic purposes
by eliminating the extra cable run necessary when both anode and dynode signals
are used. Packaged 12 channels per module, the 612A offers substantial savings
in bin space and is di- rectly compatible with standard LeCroy 12-channel
ADC's and multichannel dis- criminators.

A new high-speed operational amplifier circuit design makes the performance
of the amplifier virtually independent of external variables such as supply
voltages or temperature. Input and output DC levels remain negligibly small
even when the module is moved from bin to bin, or under extremes of operating
temperature. There is virtually no warm-up drift on turn-on. These stability
characteristics, to- gether with the excellent linearity, speed and noise
characteristics of the circuit, come very close to the ideal of a "transparent
gain" element that simply magnifies the input without significant distortion
or operating constraints.

The Model 612A normally operates from +6, +/-12, and -24 volts. A rear-panel
switch permits operation from -6 instead of -12 volts for those applications
in which -6 volts is easily available and where a moderate saving in power
consumption is more important than dynamic range. When operated from -6 volts,
maximum output amplitude is reduced from -5 to -2 volts. In either case,
the large output levels available reduce recovery time problems associated
with overload.